It has been my experience that romantic can be scary, and a lot of hard work. One may be afraid to loose one they care deeply for or even deeply love. Those that are in or have had a romantic relationship all know the fear of getting hurt, the rejection, or even the sad realization that their relationship is over, which is where the break up comes in. A couple can go many ways, staying friends, not speaking, friends with benefits, or leaving the future open to the possibility of getting back together/seeing what the future holds.
I have had several romantic relationships over the past few years. I am currently single. I only remain in contact with two of my ex boyfriends. All but one ended on good terms, we'd stay friends for a while but slowly drift as time went on. In fact one of my ex-boyfriends is currently my best, and closest (all non sexually) friends. The one ex-boyfriend that ended on bad terms, he wanted to have sex, and I was not ready, so I wouldn't give in just to keep him. He got upset and left, we ended up later down the road building a friendship. We ended up drifting and no longer have any sort of contact.
But I believe with enough compromise, communication, hard work, trust, a feeling of love & security, a feeling that neither party is rushed/pressured/only wanted for one thing and one thing only, and a good mixture of two people, I believe anyone can have a happy romantic relationship. That does not always mean that it will last forever though. Life does happen, and no one has the crystal ball to look into the future and predict any outcome. And as life changes, so do we.